using System;
using System.Linq;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
using System.Numerics;
using Point = System.Numerics.Complex;
using Number = System.Int64;
namespace Program
{
    public class Solver
    {
        //面倒問題やめろ
        public void Solve()
        {
            var h = sc.Integer() + 2;
            var w = sc.Integer() + 2;
            var map = Enumerate(h, x => new char[w]);
            for (int i = 0; i < h; i++)
                for (int j = 0; j < w; j++)
                    map[i][j] = '.';
            for (int i = 1; i < h - 1; i++)
                for (int j = 1; j < w - 1; j++)
                    map[i][j] = sc.Char();

            var set = new DisjointSet(h * w);
            {
                for (int i = 0; i < h; i++)
                    for (int j = 0; j < w; j++)
                    {
                        if (map[i][j] != 'x') continue;
                        for (int dx = -1; dx <= 1; dx++)
                            for (int dy = -1; dy <= 1; dy++)
                            {
                                var nx = i + dx;
                                var ny = j + dy;
                                if (nx < 0 || nx >= h || ny < 0 || ny >= w) continue;
                                if (map[nx][ny] == 'x')
                                {
                                    set.Unite(i * w + j, nx * w + ny);
                                }
                            }
                    }
            }
            var GO = Enumerate(h * w, x => new Queue<int>());
            for (int i = 0; i < h; i++)
                for (int j = 0; j < w; j++)
                {
                    if (map[i][j] != 'x') continue;
                    GO[set[i * w + j]].Enqueue(i * w + j);
                }
            GO[0].Enqueue(0);
            var used = new bool[h * w];


            var G = new HashMap<int, List<int>>();
            var SZ = new HashMap<int, int>();
            SZ[0] = 0;
            var go = new Queue<int>();
            go.Enqueue(0);

            {
                int[] dx = { 1, 0, -1, 0 };
                int[] dy = { 0, 1, 0, -1 };

                var root = Enumerate(h * w, x => -114514);
                while (go.Any())
                {
                    var p = go.Dequeue();
                    Debug.WriteLine(p);
                    var next = new HashSet<int>();
                    foreach (var x in GO[p])
                        used[x] = true;

                    while (GO[p].Any())
                    {
                        var u = GO[p].Dequeue();
                        var ux = u / w;
                        var uy = u % w;
                        for (int k = 0; k < 4; k++)
                        {
                            var nx = ux + dx[k];
                            var ny = uy + dy[k];
                            if (nx < 0 || nx >= h || ny < 0 || ny >= w) continue;
                            if (used[nx * w + ny]) continue;
                            used[nx * w + ny] = true;
                            if (map[nx][ny] == '.')
                            {
                                GO[p].Enqueue(nx * w + ny);
                            }
                            else
                            {
                                if (set[p] == set[nx * w + ny])
                                {
                                    GO[p].Enqueue(nx * w + ny);

                                }
                                else
                                {
                                    root[nx * w + ny] = p;
                                    next.Add(set[nx * w + ny]);
                                }
                            }

                        }
                    }
                    foreach (var x in next) go.Enqueue(x);
                }

                for (int i = 0; i < h * w; i++)
                {
                    if (root[i] != -114514 && set[i] == i)
                    {
                        G[root[i]].Add(i);
                        SZ[i] = set.Size(i);
                    }

                }
            }
            //use
            var dp = Enumerate(2, x => new HashMap<int, long>());

            Func<int, int, long> dfs = null;
            dfs = (cur, k) =>
              {
                  if (dp[k].ContainsKey(cur))
                      return dp[k][cur];

                  var ret = 0L;
                  if (k == 0)
                  {
                      ret += SZ[cur];
                      foreach (var to in G[cur])
                      {
                          ret += dfs(to, 1);
                      }
                  }
                  else
                  {
                      foreach (var to in G[cur])
                      {
                          ret += Math.Max(dfs(to, 0), dfs(to, 1));
                      }
                  }

                  return dp[k][cur] = ret;

              };
            IO.Printer.Out.WriteLine(dfs(0, 1));
        }

        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());
        static T[] Enumerate<T>(int n, Func<int, T> f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(i); return a; }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}

#region main
static class Ex
{
    static public string AsString(this IEnumerable<char> ie) { return new string(System.Linq.Enumerable.ToArray(ie)); }
    static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") { return string.Join(st, ie); }
    static public void Main()
    {
        var solver = new Program.Solver();
        solver.Solve();
        Program.IO.Printer.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;
    public class Printer : StreamWriter
    {
        static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; }
        public static Printer Out { get; set; }
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
        public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
        public void Write<T>(string format, T[] source) { base.Write(format, source.OfType<object>().ToArray()); }
        public void WriteLine<T>(string format, T[] source) { base.WriteLine(format, source.OfType<object>().ToArray()); }
    }
    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }
        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }
        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } }
            return buf[ptr++];
        }
        public char Char() { byte b = 0; do b = read(); while ((b < 33 || 126 < b) && !isEof); return (char)b; }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != 0 && b != '-' && (b < '0' || '9' < b));
            if (b == 0) return long.MinValue;
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = ret * 10 + b - '0';
            }
        }
        public int Integer() { return (isEof) ? int.MinValue : (int)Long(); }
        public double Double() { var s = Scan(); return s != "" ? double.Parse(s, CultureInfo.InvariantCulture) : double.NaN; }
        private T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n) { return enumerate(n, Char); }
        public string[] Scan(int n) { return enumerate(n, Scan); }
        public double[] Double(int n) { return enumerate(n, Double); }
        public int[] Integer(int n) { return enumerate(n, Integer); }
        public long[] Long(int n) { return enumerate(n, Long); }
    }
}
#endregion

#region DisjointSet
public class DisjointSet
{
    public int[] par, ranks, count;
    public DisjointSet(int n)
    {
        par = new int[n];
        count = new int[n];
        for (int i = 0; i < n; i++)
        {
            par[i] = i;
            count[i] = 1;
        }
        ranks = new int[n];
    }
    public int this[int id] { get { return (par[id] == id) ? id : this[par[id]]; } }
    public bool Unite(int x, int y)
    {
        x = this[x]; y = this[y];
        if (x == y) return false;
        if (ranks[x] < ranks[y])
        {
            par[x] = y;
            count[y] += count[x];
        }
        else
        {
            par[y] = x;
            count[x] += count[y];
            if (ranks[x] == ranks[y])
                ranks[x]++;
        }
        return true;
    }
    public int Size(int x) { return count[this[x]]; }
    public bool IsUnited(int x, int y) { return this[x] == this[y]; }

}
#endregion

#region HashMap
public class HashMap<K, V> : Dictionary<K, V>
where V : new()
{
    public HashMap() : base() { }
    public HashMap(int cap) : base(cap) { }
    new public V this[K i]
    {
        get
        {
            V v;
            return TryGetValue(i, out v) ? v :
            base[i] = new V();
        }
        set { base[i] = value; }
    }
}
#endregion